The invention relates to the field of footwear for daily use, sports footwear, including footwear for running, jumping, skating, skiing, bicycling etc., and footwear used as a means of rehabilitation for restoration of workability of leg muscles.
Usually footwear serves for protection of human legs against external influences. According to its intended purpose, footwear typically comprises a solid and strong enough sole and an upper part (an ‘upper’) connected to the sole, and ensuring retention of the footwear on the feet, and protecting them, if necessary from environmental influences. The rear end of the upper in the majority of footwear types is supplied with rigid inserts forming a back. The forms of execution of the sole and the upper depend on the purpose of footwear, and can vary (e.g. see Bolshaya Sovetskaya Entsiklopediya—The Great Soviet Encyclopedia, herein further referred to as BSE. Obuv.Http://slovari.yandex.ru/dict/bse/article/0005 4).
The specified footwear does not influence appreciably the way of a person's movement. During the walking a person raises one leg, leaning that moment on the second one, transfers the raised leg forward and lowers it on the bearing surface (ground). Then the process is repeated (BSE. http://slovari.yandex.ru/dict/bse/article/00086/96200.htm?text=%D1%85%D0%BE%D0% B4% D1%8C% D0%B1% D0%B0).
One of the features of a person's way of moving in comparison with the majority of other mammalians is the character of contact of a leg with the bearing surface. A person transferring his/her weight on the other leg leans at the first on the foot's heel bone and then transfers the load (person's weight) on the foot as a whole.
The defect of such a way of moving in walking is an irrational energy expenditure. The gravitational component at each step is completely lost. The body organs that are able to partially store the energy, for example the Achilles tendon and ankle joint, are working not effectively enough.
The majority of animals moves in another way. The primary contact with the bearing surface (ground) is carried out by them by the front (forward) part of the leg (paw), which means that the ankle joints of the feet work for twisting, the sinews are stretched accumulating energy, and then an energy release and additional repulsing of the leg (paw) occur, carrying out the following step or jump.
With a person, the primary support on the toes and the leg's instep bone occurs only occasionally, for example at running.
There are well known a plenty of various devices designed to increase a person's moving efficiency based on energy accumulation by ad elastic element capable of deformation at walking and energy release at return of this element to an initial position.
Footwear used mainly for sports is known, including a support device executed as a boot enveloping a shank with an auxiliary system in the form of a spring-loaded device with levers springed up by helix spiral springs, wherein the major lever is positioned close to the boot's sole with a possibility of turning and longitudinal displacement with regard to that axis, and whereat a base part of the major lever projects down relatively to the boot sole (see patent of the Russian Federation RU2238125, priority 27 Apr. 1998 GB).
During the walking, a user raises a leg and the boot thereon so that the boot and the protruding lever do not touch the ground. Then, in movement of the boot downwards, the major lever, first touching the ground, turns, overcoming the reaction of the spring, causing deformation of the spiral spring with accumulation of energy, which will help in the further upward movement of the boot.
A shortcoming of the above-described footwear and the way of movement while wearing it is a significant complexity of its design and inconvenience of the movement, in particular related to the necessity of raising the footwear to a considerable height.
A similar principle is used in designing a device according to U.S. Pat. No. 6,840,893, filed 29 Apr. 2002. The aforementioned device is also based on the use of springs deformed during the lowering of a leg onto the ground and the returning of energy when the leg is further raised. However such design is also bulky and unacceptable for use in the daily life.
There is known footwear designed as a high boot supplied with a device for increasing a jumping ability, comprising a support element ensuring a reliable fixation of the foot and another element, embracing the calf and connected with the first element, providing for a turn, wherein a pivotal unit is disposed along the same axis with the ankle joint. Both elements are connected to each other by an expansion spring (Patent of Germany DE 4038511, priority 3 Dec. 1990). The deficiencies of a device designed in such a way are similar to the ones of the above mentioned prior art devices: the complexity of design, inconvenience of operation, impracticability of use in the daily life. The way of moving while wearing such footwear requires significant efforts, special skills and advanced coordination abilities.
In the instant inventor's opinion, a related art footwear most close to the present invention is taught in U.S. Pat. No. 6,840,893 filed 17 Jul. 2003. The related art footwear (further called ‘prototype’) includes a device for increasing the jumping ability of the wearer. The prototype includes a support platform capable of fixation of the foot position. The rear part of the platform is connected by means of a vertical element to an element of fixation of the footwear on the calf. The lower part of platform is hingedly coupled by means of a lever with the lower part of an arc-shaped plate spring supplied with an overlay with a radial and wear-proof surface. The upper part of platform is rigidly coupled with the element of fixation of the footwear on the calf.
A person's walking in the aforesaid footwear is carried out by means of a sequential raising and lowering of the feet. With lowering a foot, the arched spring is bent, and its bottom end comes nearer to the platform. At raising the foot, the spring is freed and pushes the foot fixed within the device forward and upward.
The spurt in jumping or at the moment of a takeoff when running in the footwear with energy accumulation is actualized by means of compulsory deformation (loading) of the spring and subsequent repulsing the foot from the ground with the use of energy freed due to the release of the spring.
The ankle joint and the Achilles tendon operation do not influence the jumping efficiency. The deformation of the spring is effected only at the expense of a person's weight. The use of an arched spring has allowed avoiding spiral springs that has increased the efficiency of energy accumulation and reliability of the device's operation.
However the character of landing the foot with the device has not just changed but has also become more expressed: a primary support on the back part of the foot, and quick transfer of the body mass on the whole feet.
The use of footwear with such a device will entail the following drawbacks:                Substantial complexity of design of the footwear equipped with the specified mechanism;        Impossibility to increase the efficiency of the usual walking process, complexity of the use of the footwear in the daily life;        The process of walking requires raising the legs to a significant height;        The process of walking requires significant efforts, special skills and good movement coordination of the user.        In addition, such footwear cannot be used for other kinds of movement, for example, for skating, skiing etc.        